Mike Wallace, one of the original correspondents of 60 Minutes, has died at 93. Wallace worked for the program for four decades and entered semi-retirement in 2006. Since then, Wallace appeared intermittently on the show to interview such contentious figures as Jack Kevorkian and Mahmoud Ahmadinejad. His most recent 60 Minutes interview was with Roger Clemens in 2008.

Wallace's colleague Morley Safer penned a piece commemorating his career as a respected (and sometimes feared) journalist. As Safer notes, Wallace confronted some of the most powerful and dangerous figures in the world, challenging them with deeply incisive questions.

Wallace took to heart the old reporter's pledge to comfort the afflicted and afflict the comfortable. He characterized himself as "nosy and insistent."

So insistent, there were very few 20th century icons who didn't submit to a Mike Wallace interview. He lectured Vladimir Putin, the President of Russia, on corruption. He lectured Yassir Arafat on violence.

He asked the Ayatollah Khoumeini if he were crazy.

Assuming his burial wishes are granted, Wallace's epigraph will read, "Tough But Fair."